Hi Elin,
Further research suggests that if the Leeds City Square broadcast event didn't take place on 14 Nov. or 15 Nov. 1922, as mentioned in my earlier post to this forum, then it took place 17 months later, on 23 April, 1924. That day, King George V and Queen Mary opened the British Empire Exhibition at Wembley, Middlesex and King George made the first radio broadcast by a British monarch, which was relayed to major cities around Britain, including Leeds. The Daily Mail (London) claimed credit for publicising the event and making special arrangments for massed crowds to hear the King's speech via the radio broadcast. Trust this may help your search when you visit Leeds Central Library tomorrow.
Cheers
AL